IQ 180

180 is 5.33 standard deviations above the mean. On a bell curve that works out to about 1 in 21 million people, which would mean about 3 in the UK and about 390 worldwide. The bell curve is a model, though, and at this height it is doing most of the work.

No test has enough people in its norm sample to check its accuracy at 180. In a 2,200-person sample the bell curve expects effectively nobody at 180 or higher.

Real populations may not follow the bell curve perfectly in the far tails, so rarity figures this extreme are illustrations, not head counts.

A 180 almost never comes from a modern, supervised adult test. It usually comes from somewhere like this:

• Ratio IQ. Early childhood tests divided mental age by real age. A 6-year-old solving puzzles like a typical 10.8-year-old got a ratio IQ of 180. Modern deviation IQs do not work this way.
• Different scales. Some tests use a standard deviation of 24, so a 180 there is about 150 on the usual SD 15 scale.
• Unnormed online quizzes. A test with no norm data can print any number. Very high outputs usually say more about the scoring than the person.

Nobody in history has a measured IQ of 180. The highest estimates on this site, for figures such as Isaac Newton and Leonardo da Vinci, come from reading their work and lives, not from tests. 42 profiles here are estimated at 160 or more.

Estimates this high mostly reflect how extraordinary the achievement was. That is a different thing from how someone would perform on a timed reasoning test.

Scoring 180 or higher is a 0.0000048% share of everyone. Scaled up to whole populations, that works out as:

Compare the neighbours: 175 or higher is about 1 in 3.5 million, 180 or higher is 1 in 21 million, and 185 or higher is 1 in 140 million. Each point up here adds roughly 45% to the rarity.

What your 180 could really be. Even a good supervised test has a margin of error of roughly 5 points either side, and far more at this height. A true score from 175 to 185 would span rarities from 1 in 3.5 million to 1 in 140 million.

Which scale was it on? Score reports do not always say. On the common SD 15 scale your 180 stands as it is. If the report used SD 16 it equals about 175, and if it used SD 24 about 150. The percentile follows the converted number.

Estimates this high are reserved for a small group of scientists, artists and thinkers. These sit near 180. Every figure below is a retrospective estimate, not a measured score. Open a profile to see the evidence and how confident anyone can be.

The scores one and five points either side of 180, plus the round numbers from 100 to 150, side by side. Tap any score for its full page.